This invention relates to transfer lines that can be used for conveying high temperature gases.
In many operations such as reforming, there are conduits or lines that are to convey high temperature gases. In the past, these transfer lines have typically been comprised of a high pressure resistant outer shell, a metal inner lining, and intermediate lining of insulating concrete. At temperatures in the range of 1375.degree. to 1825.degree. F., such lines are subject to deterioration and failure. Particularly at the higher temperatures metal linings, even those of stainless steel, are known to be especially subject to warpage and deformation which can be followed by erosion of the insulating layer and in turn to possible rupture of the outer pressure shell.
An object of the present invention is to provide an improved process gas transfer line that has greater resistance to failure and that can be installed within in existing plants with a minimum amount of modification of the plant.
In another aspect, the present invention relates to a method for forming such a gas process transfer line.
In still another aspect, the present invention relates to an ammonia plant having the improved transfer line as the transfer line between the secondary reformer and the waste heat boiler.